Creating VBA Macros with User Interface in CorelDRAW and Corel DESIGNER

This article walks the user through the steps of creating a simple Image Resizer macro which takes images from a specified folder, opens them in Corel PHOTO-PAINT, resizes them to specific dimensions and saves them to a different folder. Even though the example described below is designed for Corel PHOTO-PAINT X7, the same principles can be easily applied to CorelDRAW and Corel DESIGNER.

The macro project will contain a simple macro that shows a dialog box which allows the user to enter the location of images to process, required dimensions and the output folder.

First create a new macro project for Image Resizer macro. For this, open the Macro Manager docker (Alt-Shitf-F11), select “Visual Basic for Applications” in the list, right-click and select “New Macro Project…”

When the “Save As” dialog box appears, enter “ImageResizer” in the file name. This will create a new macro project called ImageResizer.gms and it will be loaded into the Macro Manager docker now:

Right-click “ImageResizer” and select “New Module” from the pop-up menu and rename the created module to “Resizer”.

Finally, right-click the “Resizer” mode and select “New Macro” which will open the VBA editor with the new “Macro1” open:

Rename the macro and show a simple message by editing the macro code to be:

Now the basic macro project is set up. You can try running this macro by double-clicking the “Start” macro under ImageResizer > Resizer in Macro Manager docker:

Now that the macro project is set up, it’s time to add a user interface to it. Switch back to VBA editor, select the “Resizer” module in VBA’s Project Explorer docker (Ctrl-R), right-click it and select Insert > UserForm from the pop-up menu:

A new user form will be added to the macro project and the form designer window will open:

Note the Properties docker in VBA shows various customization options for the user form. For example, the Caption property specifies the text shown in the title bar of the form. Replace the default “UserForm1” string with “Image Resizer”.

Now switch to “Resizer” macro module editor (double click on “Resizer” under “Modules” in the VBA Project Explorer). And change the macro to show the new dialog box instead of the “Hello, world” message box but editing the code to read:

Now you can run the macro to see how the new dialog box looks like. Run it from Corel PHOTO-PAINT’s Macro Manager docker or you can do this directly from VBA editor by placing text cursor anywhere within the Start subroutine code and hitting F5 to run it:

Now that a dialog box can be shown by Image Resizer macro, it’s time to add some controls to it. Toolbox in VBA form editor contains all the user controls currently available:

The toolbox contains the following controls: text label, textbox, combobox, listbox, checkbox, radio button, toggle button, group box, command button, tab strip, multipage control, scroll bar, spin button, image. More controls can be added to the toolbox from third-party control libraries.

To add a control to a form, just drag the control out of toolbox and drop it onto the form at the desired location. Once dropped onto the form, controls can be selected, moved and resized just like objects in CDGS applications. Clicking an already-selected control allows to edit the contents of the control (e.g. the caption of a text label control or the text of a text box).

Place label controls, text boxes, command buttons and the checkbox as shown in the following screenshot:

When a control is selected, you can also give it a more descriptive name to identify the control in the macro code, because the automatic generated control names such as TextBox1 and Label2 are not very descriptive. The control name can be specified in the “(Name)” property in the Properties docker.

The following controls are used in the form, including their type and name (left-to-right and top-to-bottom):

Now that all the controls are properly placed on the form, try running the macro again to see how the real form will look like when run from Corel PHOTO-PAINT’s Macro Manager docker:

However you will notice that clicking any buttons has no effect because there is no code written to specify what should happen when a button is clicked.

This can be done simply by double-clicking a command button in VBA form designer. For example, double-click the “Resize Images” button. This will open the code window for the user form and add an event handler for mouse click for cmdResize control:

Change the implementation of cmdResize_Click() event handler to be the following:

This adds a simple code to show a message box when the button is clicked:

Now implement the Browse buttons for source and destination folders. This requires a “Browse For Folder” dialog from Windows which is not available in VBA directly. However VBA can use low-level Windows API functions, and there is already code available for this which is part of Corel PHOTO-PAINT’s HTMLSlideshow macro. You can just copy that code directly from that macro into your own. Expand the HTMLSlideshow macro project in VBA’s Project Explorer and locate the “FolderPicker” module. Select and drag it into the ImageResizer project:

This will copy the FolderPicker module to ImageResizer and its code can now be used inside our macro too.

Add the two button click event handlers for both Browse… buttons and provide their implementations as follows:

Here, both event handlers are pretty much identical, except that they use different text controls (txtSourceFolder and txtDestFolder) to obtain the current folder name entered in those controls, call BrowseForFolderDlg() function from FolderPicker module and the new folder path returned is set back into the respective text box.

Now we are ready to implement the main image processing function to do all the image manipulation. Change the cmdResize_Click() function to be the following:

This function takes the input from source and destination folder text boxes and validates that they contain valid folder names. Then it converts the required width and height of the image from the content of the text boxes (strings) to integer numbers which will be used when resizing images.

Finally, it calls the ResizeImages function to do the actual image conversion. After all the images are processed inside ResizeImages, the dialog is closed by invoking the Unload method.

ResizeImages iterates over all the files inside a folder identified by sourceFolder, opens each one of them in Corel PHOTO-PAINT, resize each image and saves them as JPEGs into the output folder specified by destFolder.

When maintainAspect variable is set to True, there is additional logic to preserve the image aspect ratio.

Now we have a fully functional macro that shows a custom dialog, accepts user input and processes a bunch of images using Corel PHOTO-PAINT. Feel free and experiment with the source code and build more complex solutions to the problems you may encounter in your day-to-day work.